Bathroom renovation help

[Lionofthesouth]

Hello, new member. Not a builder. Not even a competent DIYer.
Moved into my partners house a while ago. Stripped the tiles off bathroom walls(it’s basically like an old coal shed on back of house). Behind the tiles was wet. Bricks were soaked. In places Plasterboard was dot and dabbed? direct to brickwork. In other places there was like a Sandy (red) mix and plasterboard on top of that(regular boards I think). The walls are very uneven. Some places it is an inch or so difference.

Time has come when we can afford to have the room finished. Just wondering what route we should take? The brickwork is not in great condition. Can brickwork be plastered over? Does it need to be boarded first? How are the uneven surfaces dealt with?

Thinking of turning it into a shower room as it is quite small and only fits a corner bath which is pretty small, so assume need electric installed before plastering?

Thanks for any help. Can provide pics if needed.

 

[stevethespreader]

Downstairs bathrooms are notorious for beong cold and damp epec ones that are stuck on the back of the house behind the kitchen show the pictures and maybe someone can give you some help